| abstract |
(57) [Summary] The present invention provides the following formula (I) [Wherein, R 1 is a group represented by the formula (A) [Wherein, R 3 , R 4 and R 5 each represent the same or different hydrogen, etc.] R2 is a group capable of forming a chemical bond with the resin, and may be protected by a conventional protecting group. A is a lower alkylene group; X is a leaving group; m represents an integer of 0 or 1, provided that when R 1 is a group represented by the formula (A), A represents a (C 2 -C 6 ) alkylene group; For the linker represented by |